Warpfeed with normal forgrip and grip frame?

How does a warpfeed work with the standard grip frame and a normal foregrip(not extended) or maybe a 15 degree angled forgrip on a mag? Can you still use the foregrip effectively? Also will I run into any problems with a warpfeed being a right handed player with a hopper left? Does it have to feed from the bottom of the powerfeed?